Abstract: A process for enriching a liquid with oxygen by introducing the liquid into an oxygen enriching vessel, subdividing the liquid, subjecting the interior of the vessel to an oxygen pressure of at least about 20 psi, conducting the introduced water in a substantially flowing contact with the oxygen, and recovering the water under oxygen pressure when it is to be bottled. The process is carried out in oxygen enriching apparatus having an oxygen enriching vessel, a number of horizontal trays vertically spaced apart from each other and having a central opening, a liquid supply tube ranging into the interior of the enriching vessel through the central openings, means for discharging liquid from the tube onto a tray, an oxygen supply source for providing the oxygen to the vessel, and a liquid outlet for the removal of the oxygenated liquid. The liquids oxygenated by the invention are used in various aerobic and therapeutic processes.